Hibiscus tiliaceus is a species of flowering

Flowering plant

The flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...

 tree

Tree

A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...

 in the mallow

Malva

Malva is a genus of about 25–30 species of herbaceous annual, biennial, and perennial plants in the family Malvaceae , one of several closely related genera in the family to bear the common English name mallow. The genus is widespread throughout the temperate, subtropical and tropical regions of...

 family, Malvaceae

Malvaceae

Malvaceae, or the mallow family, is a family of flowering plants containing over 200 genera with close to 2,300 species. Judd & al. Well known members of this family include okra, jute and cacao...

, that is native to the Old World

Old World

The Old World consists of those parts of the world known to classical antiquity and the European Middle Ages. It is used in the context of, and contrast with, the "New World" ....

 tropics

Tropics

The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately  N and the Tropic of Capricorn in the southern hemisphere at  S; these latitudes correspond to the axial tilt of the Earth...

. Common names include Sea Hibiscus, Beach Hibiscus, Coastal (or Coast) Hibiscus, Coastal (or Coast) Cottonwood, Green Cottonwood, Native Hibiscus, Native Rosella, Cottonwood Hibiscus, Kurrajong, Sea Rosemallow, Norfolk Hibiscus, Hau (Hawaiian

Hawaiian language

The Hawaiian language is a Polynesian language that takes its name from Hawaii, the largest island in the tropical North Pacific archipelago where it developed. Hawaiian, along with English, is an official language of the state of Hawaii...

), and Purau (Tahitian

Tahitian language

Tahitian is an indigenous language spoken mainly in the Society Islands in French Polynesia. It is an Eastern Polynesian language closely related to the other indigenous languages spoken in French Polynesia: Marquesan, Tuamotuan, Mangarevan, and Austral Islands languages...

). The specific epithet, "tiliaceus", refers to its resemblance to the related Tilia

Tilia

Tilia is a genus of about 30 species of trees native throughout most of the temperate Northern Hemisphere. The greatest species diversity is found in Asia, and the genus also occurs in Europe and eastern North America, but not western North America...

species.

Description

H. tiliaceus reaches a height of 4–10 m (13.1–32.8 ft), with a trunk up to 15 cm (5.9 in) in diameter. The flower

Flower

A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

s of H. tiliaceus are bright yellow with a deep red centre upon opening. Over the course of the day, the flowers deepen to orange and finally red before they fall. The branches of the tree often curve over time.

Range and habitat

H. tiliaceus is a common coast

Coast

A coastline or seashore is the area where land meets the sea or ocean. A precise line that can be called a coastline cannot be determined due to the dynamic nature of tides. The term "coastal zone" can be used instead, which is a spatial zone where interaction of the sea and land processes occurs...

al plant in Eastern and Northern Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

, Oceania

Oceania

Oceania is a region centered on the islands of the tropical Pacific Ocean. Conceptions of what constitutes Oceania range from the coral atolls and volcanic islands of the South Pacific to the entire insular region between Asia and the Americas, including Australasia and the Malay Archipelago...

 and Southeast Asia

Southeast Asia

Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...

. It has become naturalized

Introduced species

An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...

 in parts of the New World

New World

The New World is one of the names used for the Western Hemisphere, specifically America and sometimes Oceania . The term originated in the late 15th century, when America had been recently discovered by European explorers, expanding the geographical horizon of the people of the European middle...

, such as Florida

Florida

Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...

, Puerto Rico

Puerto Rico

Puerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...

, and the Virgin Islands

Virgin Islands

The Virgin Islands are the western island group of the Leeward Islands, which are the northern part of the Lesser Antilles, which form the border between the Caribbean Sea and the Atlantic Ocean...

. It is uncertain if the species is native to Hawaii

Hawaii

Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

, as it may have been introduced

Canoe plants

Canoe plants, or Polynesian introductions, are plants taken from ancient Polynesia and transplanted to other Pacific IslandsThe term is particularly used to refer to plants brought to Hawaii 1,700 years ago by Polynesian explorers....

 by the Polynesia

Polynesia

Polynesia is a subregion of Oceania, made up of over 1,000 islands scattered over the central and southern Pacific Ocean. The indigenous people who inhabit the islands of Polynesia are termed Polynesians and they share many similar traits including language, culture and beliefs...

ns. H. tiliaceus can be found at elevations from sea level to 800 m (2,624.7 ft) in areas that receive 900 – of annual rainfall. It is commonly found growing on beach

Beach

A beach is a geological landform along the shoreline of an ocean, sea, lake or river. It usually consists of loose particles which are often composed of rock, such as sand, gravel, shingle, pebbles or cobblestones...

es, by rivers

Riparian zone

A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the fifteen terrestrial biomes of the earth. Plant habitats and communities along the river margins and banks are called riparian vegetation, characterized by...

 and in mangrove

Mangrove

Mangroves are various kinds of trees up to medium height and shrubs that grow in saline coastal sediment habitats in the tropics and subtropics – mainly between latitudes N and S...

 swamp

Swamp

A swamp is a wetland with some flooding of large areas of land by shallow bodies of water. A swamp generally has a large number of hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodical inundation. The two main types of swamp are "true" or swamp...

s. Sea Hibiscus is well adapted to grow in coastal environment in that it tolerates salt

Halophyte

A halophyte is a plant that grows where it is affected by salinity in the root area or by salt spray, such as in saline semi-deserts, mangrove swamps, marshes and sloughs, and seashores. An example of a halophyte is the salt marsh grass Spartina alterniflora . Relatively few plant species are...

 and waterlogging and can grow in quartz

Quartz

Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...

 sand

Sand

Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...

, coral sand

Coral sand

Coral sand is sand of particles originating in tropical and sub-tropical marine environments from bioerosion of limestone skeletal material of marine organisms. One example of this process is that of parrot fishes which bite off pieces of coral, digest the living tissue, and excrete the inorganic...

, marl

Marl

Marl or marlstone is a calcium carbonate or lime-rich mud or mudstone which contains variable amounts of clays and aragonite. Marl was originally an old term loosely applied to a variety of materials, most of which occur as loose, earthy deposits consisting chiefly of an intimate mixture of clay...

, limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

, and crushed basalt

Basalt

Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...

. It grows best in slightly acid

Acid

An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...

ic to alkali

Alkali

In chemistry, an alkali is a basic, ionic salt of an alkali metal or alkaline earth metal element. Some authors also define an alkali as a base that dissolves in water. A solution of a soluble base has a pH greater than 7. The adjective alkaline is commonly used in English as a synonym for base,...

ne soil

Soil

Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

s (pH

Soil pH

The soil pH is a measure of the acidity or basicity in soils. pH is defined as the negative logarithm of the activity of hydrogen ions in solution. It ranges from 0 to 14, with 7 being neutral. A pH below 7 is acidic and above 7 is basic. Soil pH is considered a master variable in soils as it...

 of 5-8.5).

Uses

The wood of H. tiliaceus has a specific gravity

Specific gravity

Specific gravity is the ratio of the density of a substance to the density of a reference substance. Apparent specific gravity is the ratio of the weight of a volume of the substance to the weight of an equal volume of the reference substance. The reference substance is nearly always water for...

 of 0.6. It has been used in a variety of applications, such as seacraft construction, firewood

Firewood

Firewood is any wood-like material that is gathered and used for fuel. Generally, firewood is not highly processed and is in some sort of recognizable log or branch form....

, and wood carving

Wood carving

Wood carving is a form of working wood by means of a cutting tool in one hand or a chisel by two hands or with one hand on a chisel and one hand on a mallet, resulting in a wooden figure or figurine, or in the sculptural ornamentation of a wooden object...

s. Its tough bark can be made into durable rope

Rope

A rope is a length of fibres, twisted or braided together to improve strength for pulling and connecting. It has tensile strength but is too flexible to provide compressive strength...

 and for sealing cracks in boats. The bark and roots may be boiled to make a cooling tea to cool fever

Fever

Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...

s, and its young leafy shoot

Shoot

Shoots are new plant growth, they can include stems, flowering stems with flower buds, and leaves. The new growth from seed germination that grows upward is a shoot where leaves will develop...

s may be eaten as vegetables. Native Hawaiians

Native Hawaiians

Native Hawaiians refers to the indigenous Polynesian people of the Hawaiian Islands or their descendants. Native Hawaiians trace their ancestry back to the original Polynesian settlers of Hawaii.According to the U.S...

 used the wood to make iako

Aka (sailing)

The aka of a multihull sailboat is a member of the framework that connects the hull to the ama . The term aka originated with the proa, but is also applied to modern trimarans....

(spars) for waa (outrigger canoe

Outrigger canoe

The outrigger canoe is a type of canoe featuring one or more lateral support floats known as outriggers, which are fastened to one or both sides of the main hull...

s), mouo (fishing net

Fishing net

A fishing net or fishnet is a net that is used for fishing. Fishing nets are meshes usually formed by knotting a relatively thin thread. Modern nets are usually made of artificial polyamides like nylon, although nets of organic polyamides such as wool or silk thread were common until recently and...

 floats), and au koi (adze

Adze

An adze is a tool used for smoothing or carving rough-cut wood in hand woodworking. Generally, the user stands astride a board or log and swings the adze downwards towards his feet, chipping off pieces of wood, moving backwards as they go and leaving a relatively smooth surface behind...

 handles). Kaula ilihau (cordage) was made from the bast fiber

Bast fibre

Bast fibre or skin fibre is plant fibre collected from the phloem or bast surrounding the stem of certain, mainly dicotyledonous, plants. They support the conductive cells of the phloem and provide strength to the stem...

s. Hau would be used to make ama

Ama (sailing)

The term ama is a word in the Polynesian and Micronesian languages to describe the outrigger part of a canoe to provide stability. Today, among the various Polynesian countries, the word ama is often used together with the word vaka or waka or va'a , cognate words in various Polynesian languages...

(canoe floats) if wiliwili

Wiliwili

Wiliwili is a species of flowering tree in the pea family, Fabaceae that is endemic to the Hawaiian Islands. It is the only species of Erythrina that naturally occurs there. It is typically found in dry forests on leeward island slopes up to an elevation of .Wiliwili is occasionally seen in...

(Erythrina sandwicensis) was unavailable.

H. tiliaceus is widely used in Asian countries as a subject for the art of bonsai

Bonsai

is a Japanese art form using miniature trees grown in containers. Similar practices exist in other cultures, including the Chinese tradition of penjing from which the art originated, and the miniature living landscapes of Vietnamese hòn non bộ...

, especially Taiwan. The finest specimens are taken from Kenting National Park

Kenting National Park

Kenting National Park is a national park located in the Hengchun Peninsula of Pingtung County, Taiwan, covering Hengchun, Checheng and Manjhou Townships. Established on January 1, 1984, it is Taiwan's oldest and southernmost national park, covering the southernmost area of the Taiwan island...

. Lending itself to free grafting

Grafting

Grafting is a horticultural technique whereby tissues from one plant are inserted into those of another so that the two sets of vascular tissues may join together. This vascular joining is called inosculation...

, the leaf size is reduced fairly quickly.

Chemistry

Cyanidin-3-glucoside is the major anthocyanin found in flowers of H. tiliaceus (Lowry, 1976). Leaves of H. tiliaceus displayed strong free radical scavenging activity and the highest tyrosinase inhibition activity among 39 tropical plant species in Okinawa. With greater UV radiation in coastal areas, there is no evidence that leaves and flowers of natural coastal populations of H. tiliaceus have stronger antioxidant properties than planted inland populations.